3AB-62100-0 Tohatsu CLAMP SCREW ASSY

Electronic Controls
Electronic Control Module
The ECM consists of two main components, the control computer (hardware) and the flash file (software). The control computer consists of a microprocessor and electronic circuitry. The flash file is the software for the control computer which contains the operating maps that define power, torque curves and smoke limits.Engine Speed Governing
Electronic governing replaces the mechanical governor. Electronic governing provides the ability to program low idle. Electronic governing improves torque control, smoke limiting, and control of engine speed. Engine speed is governed by controlling the fuel delivery, which is a function of the injection duration.Desired engine speed is a function of the input from the throttle position sensor, the input from the engine speed/timing sensor, and customer parameters. The desired engine speed and actual engine speed are used to generate the fuel delivery rate. Final desired fuel delivery rate is the lowest value between the desired fuel delivery position, the fuel delivery torque limit, the fuel delivery smoke limit, and the various derate strategies. This final fuel rate gets modified into an injection duration.Fuel Injection
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Typical fuel systemFuel is injected only while an injector solenoid is energized by a 105 volt signal from the ECM. By controlling the timing and duration of the 105 volt signal, the ECM controls the fuel injection timing, the quantity of fuel and the desired engine rpm.Injection timing depends on engine rpm, load, and other operational factors. The ECM detects the top center (TC) of each piston. The ECM sends an injection signal at the desired time.The ECM is programmed at the factory to limit the quantity of fuel that can be injected. The smoke limit fuel volume controls the fuel limit in order to control exhaust smoke. The smoke limit fuel volume is based on the maximum allowable fuel to air ratio.The delivered fuel volume is increased when the ECM senses a higher intake manifold pressure. This will allow more fuel into the cylinder. The torque limit fuel volume is a limit that is based on the engine power rating. This is similar to the rack stops and the torque spring on a mechanically governed engine. The torque limit fuel volume provides the power curves and the torque curves for a specific engine.Engine Wiring Diagram
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TypicalLocation of Components on 3606 and 3608 Engines
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Right side view (1) Enclosure for the primary ECM and for the secondary ECM (2) User interface panel (3) Harness group (rail) (4) Secondary engine speed/timing sensor (5) Primary engine speed/timing sensor
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Left side view (6) Turbocharger outlet pressure sensor
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Top view (7) Alternate location of user interface panel
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Primary ECM and secondary ECM (8) J1/P1 primary ECM (9) Primary ECM (10) J2/P2 primary ECM (11) J1/P1 secondary ECM (12) Secondary ECM (13) J2/P2 secondary ECM (14) Connector for the interconnect junction box (15) Port for the atmospheric pressure sensor (16) Connector for the harness group (rail) (17) Atmospheric pressure sensorLocation of Components on 3612 and 3616 Engines
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Left side view (18) User interface panel (19) Harness group (left rail) (20) Primary ECM and secondary ECM
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Right side view (21) Primary engine speed/timing sensor (22) Secondary engine speed/timing sensor (23) Harness group (right rail) (24) Alternate location of user interface panel
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Top and rear view (25) Turbocharger outlet pressure sensor (26) Alternate location of user interface panel (27) Connector for the harness group (right rail) (28) Connector for the harness group (left rail) (29) Enclosure for the primary ECM and for the secondary ECM (30) Connector for the user interface panel